[RFC PATCH -tip 2/2 v3] add scripts for pagecache analysis per process

From: Keiichi KII
Date: Thu Feb 04 2010 - 21:29:38 EST

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The scripts are implemented based on the trace stream scripting support.
And the scripts implement the following and depend on the page cache
tracepoints.

- pagecache hit ratio per process
- how many pagecaches each process has per each file
- how many pages are cached per each file
- how many pagecaches each process shares

To monitor pagecache hit ratio per process, run "pagecache-hit-ratio-record"
or "pref trace record pagecache-hit-ratio" to record perf data for
"pagecache-hit-ration.pl" and run "pagecache-hit-ratio-report" or
"perf trace report pagecache-usage" to display.

The below outputs show execution sample.

[process list]
o yum-3215
cache find cache hit cache hit
device inode count count ratio
--------------------------------------------------------
253:0 16 34434 34130 99.12%
253:0 198 9692 9463 97.64%
253:0 639 647 628 97.06%
253:0 778 32 29 90.62%
253:0 7305 50225 49005 97.57%
253:0 144217 12 10 83.33%
253:0 262775 16 13 81.25%
*snip*

To monitor pagecache usage per a process, run "pagecache-usage-record" or
"perf trace record pagecache-usage" to record perf data for
"pagecache-usage.pl" and run "pagecache-usage-report" or "perf trace report
pagecache-usage" to display.

The below outputs show execution sample.

[file list]
device cached
(maj:min) inode pages
--------------------------------
253:0 16 5752
253:0 198 2233
253:0 639 51
253:0 778 86
253:0 7305 12307
253:0 144217 11
253:0 262775 39
*snip*

[process list]
o yum-3215
device cached added removed indirect
(maj:min) inode pages pages pages removed pages
----------------------------------------------------------------
253:0 16 34130 5752 0 0
253:0 198 9463 2233 0 0
253:0 639 628 51 0 0
253:0 778 29 78 0 0
253:0 7305 49005 12307 0 0
253:0 144217 10 11 0 0
253:0 262775 13 39 0 0
*snip*
----------------------------------------------------------------
total: 102346 26165 1 0

>From the output, we can know some information like:

- if "added pages" > "cached pages" on process list then
It means repeating add/remove pagecache many times.
=> Bad case for pagecache usage

- if "added pages" <= "cached pages" on process list then
It means no unnecessary I/O operations.
=> Good case for pagecache usage.

- if "caches" on file list >
sum "cached pages" per each file on process list then
It means there are unneccessary pagecaches in the memory.
=> Bad case for pagecache usage

Signed-off-by: Keiichi Kii <k-keiichi@xxxxxxxxxxxxx>
Cc: Atsushi Tsuji <a-tsuji@xxxxxxxxxxxxx>
---
tools/perf/scripts/perl/bin/pagecache-hit-ratio-record | 7
tools/perf/scripts/perl/bin/pagecache-hit-ratio-report | 6
tools/perf/scripts/perl/bin/pagecache-usage-record | 7
tools/perf/scripts/perl/bin/pagecache-usage-report | 6
tools/perf/scripts/perl/pagecache-hit-ratio.pl | 75 +++++++++
tools/perf/scripts/perl/pagecache-usage.pl | 136 +++++++++++++++++
6 files changed, 237 insertions(+)

Index: linux-2.6-tip/tools/perf/scripts/perl/bin/pagecache-usage-record
===================================================================
--- /dev/null
+++ linux-2.6-tip/tools/perf/scripts/perl/bin/pagecache-usage-record
@@ -0,0 +1,7 @@
+#!/bin/bash
+perf record -c 1 -f -a -M -R -e filemap:add_to_page_cache -e filemap:find_get_page -e filemap:remove_from_page_cache
+
+
+
+
+
Index: linux-2.6-tip/tools/perf/scripts/perl/bin/pagecache-usage-report
===================================================================
--- /dev/null
+++ linux-2.6-tip/tools/perf/scripts/perl/bin/pagecache-usage-report
@@ -0,0 +1,6 @@
+#!/bin/bash
+# description: pagecache usage per process
+perf trace -s ~/libexec/perf-core/scripts/perl/pagecache-usage.pl
+
+
+
Index: linux-2.6-tip/tools/perf/scripts/perl/pagecache-usage.pl
===================================================================
--- /dev/null
+++ linux-2.6-tip/tools/perf/scripts/perl/pagecache-usage.pl
@@ -0,0 +1,136 @@
+#!/usr/bin/perl -w
+# (C) 2010, Keiichi Kii <k-keiichi@xxxxxxxxxxxxx>
+# Licensed under the terms of the GNU GPL License version 2
+
+# Display pagecache usage per a process
+
+use lib "$ENV{'PERF_EXEC_PATH'}/scripts/perl/Perf-Trace-Util/lib";
+use lib "./Perf-Trace-Util/lib";
+use Perf::Trace::Core;
+use Perf::Trace::Context;
+use Perf::Trace::Util;
+use List::Util qw/sum/;
+
+my %files;
+my %processes;
+my %records;
+
+sub trace_end
+{
+ print_pagecache_usage_per_file();
+ print "\n";
+ print_pagecache_usage_per_process();
+}
+
+sub filemap::remove_from_page_cache
+{
+ my ($event_name, $context, $common_cpu, $common_secs, $common_nsecs,
+ $common_pid, $common_comm,
+ $s_dev, $i_ino, $offset) = @_;
+ my ($f, $r) = get_record($common_comm."-".$common_pid, $s_dev, $i_ino);
+
+ delete $$f{$offset};
+ if (defined $$r{added}{$offset}) {
+ $$r{removed}++;
+ } else {
+ $$r{indirect_removed}++;
+ }
+}
+
+sub filemap::add_to_page_cache
+{
+ my ($event_name, $context, $common_cpu, $common_secs, $common_nsecs,
+ $common_pid, $common_comm,
+ $s_dev, $i_ino, $offset) = @_;
+ my ($f, $r) = get_record($common_comm."-".$common_pid, $s_dev, $i_ino);
+
+ $$f{$offset}++;
+ $$r{added}{$offset}++;
+}
+
+sub filemap::find_get_page
+{
+ my ($event_name, $context, $common_cpu, $common_secs, $common_nsecs,
+ $common_pid, $common_comm,
+ $s_dev, $i_ino, $offset, $page) = @_;
+ my ($f, $r) = get_record($common_comm."-".$common_pid, $s_dev, $i_ino);
+
+ if ($page != 0) {
+ $$f{$offset}++;
+ $$r{cached}++;
+ }
+}
+
+sub get_record
+{
+ my ($p, $dev, $inode) = @_;
+
+ unless (defined($files{$dev}{$inode})) {
+ $files{$dev}{$inode} = {};
+ }
+ $f = $files{$dev}{$inode};
+ unless (defined($records{$p}{$f})) {
+ $records{$p}{$f} =
+ {inode => $inode, dev => $dev, added => {},
+ cached => 0, removed => 0, indirect_removed => 0};
+ }
+ return $f, $records{$p}{$f};
+}
+
+sub minor
+{
+ my $dev = shift;
+ return $dev & ((1 << 20) - 1);
+}
+
+sub major
+{
+ my $dev = shift;
+ return $dev >> 20;
+}
+
+sub print_pagecache_usage_per_file
+{
+ print "[file list]\n";
+ printf(" %12s %10s %8s\n", "device", "", "cached");
+ printf(" %12s %10s %8s\n", "(maj:min)", "inode", "pages");
+ printf(" %s\n", '-' x 32);
+ while(my($dev, $file) = each(%files)) {
+ foreach my $inode (sort { $a <=> $b } keys %$file) {
+ my $count = values %{$$file{$inode}};
+ next if $count == 0;
+ printf(" %12s %10d %8d\n",
+ major($dev).":".minor($dev), $inode, $count);
+ }
+ }
+}
+
+sub print_pagecache_usage_per_process
+{
+ print "[process list]\n";
+ while(my ($pid, $v) = each(%records)) {
+ my ($sum_cached, $sum_added, $sum_removed, $sum_indirect_removed);
+ print "o $pid\n";
+ printf(" %12s %10s %8s %8s %8s %13s\n", "device", "",
+ "cached", "added", "removed", "indirect");
+ printf(" %12s %10s %8s %8s %8s %13s\n", "(maj:min)", "inode",
+ "pages", "pages", "pages", "removed pages");
+ printf(" %s\n", '-' x 64);
+ foreach my $r (sort { $$a{inode} <=> $$b{inode} } values %$v) {
+ my $added_num = scalar(keys %{$$r{added}}) == 0 ?
+ 0 : List::Util::sum(values %{$$r{added}});
+ $sum_cached += $$r{cached};
+ $sum_added += $added_num;
+ $sum_removed += $$r{removed};
+ $sum_indirect_removed += $$r{indirect_removed};
+ printf(" %12s %10d %8d %8d %8d %13d\n",
+ major($$r{dev}).":".minor($$r{dev}), $$r{inode},
+ $$r{cached}, $added_num, $$r{removed},
+ $$r{indirect_removed});
+ }
+ printf(" %s\n", '-' x 64);
+ printf(" total: %5s %10s %8d %8d %8d %13d\n", "", "", $sum_cached,
+ $sum_added, $sum_removed, $sum_indirect_removed);
+ print "\n";
+ }
+}
Index: linux-2.6-tip/tools/perf/scripts/perl/bin/pagecache-hit-ratio-record
===================================================================
--- /dev/null
+++ linux-2.6-tip/tools/perf/scripts/perl/bin/pagecache-hit-ratio-record
@@ -0,0 +1,7 @@
+#!/bin/bash
+perf record -c 1 -f -a -M -R -e filemap:find_get_page
+
+
+
+
+
Index: linux-2.6-tip/tools/perf/scripts/perl/bin/pagecache-hit-ratio-report
===================================================================
--- /dev/null
+++ linux-2.6-tip/tools/perf/scripts/perl/bin/pagecache-hit-ratio-report
@@ -0,0 +1,6 @@
+#!/bin/bash
+# description: monitor pagecache hit ratio per process
+perf trace -s ~/libexec/perf-core/scripts/perl/pagecache-hit-ratio.pl
+
+
+
Index: linux-2.6-tip/tools/perf/scripts/perl/pagecache-hit-ratio.pl
===================================================================
--- /dev/null
+++ linux-2.6-tip/tools/perf/scripts/perl/pagecache-hit-ratio.pl
@@ -0,0 +1,75 @@
+#!/usr/bin/perl -w
+# (C) 2010, Keiichi Kii <k-keiichi@xxxxxxxxxxxxx>
+# Licensed under the terms of the GNU GPL License version 2
+
+# Display pagecache hit ratio per process
+
+use lib "$ENV{'PERF_EXEC_PATH'}/scripts/perl/Perf-Trace-Util/lib";
+use lib "./Perf-Trace-Util/lib";
+use Perf::Trace::Core;
+use Perf::Trace::Context;
+use Perf::Trace::Util;
+
+my %records;
+
+sub trace_end
+{
+ print_pagecache_hit_ratio();
+}
+
+sub filemap::find_get_page
+{
+ my ($event_name, $context, $common_cpu, $common_secs, $common_nsecs,
+ $common_pid, $common_comm,
+ $s_dev, $i_ino, $offset, $page) = @_;
+ my $r = get_record($common_comm."-".$common_pid, $s_dev, $i_ino);
+
+ if ($page != 0) {
+ $$r{hit}++;
+ } else {
+ $$r{miss}++;
+ }
+}
+
+sub get_record
+{
+ my ($p, $dev, $inode) = @_;
+
+ unless (defined($records{$p}{$dev.":".$inode})) {
+ $records{$p}{$dev.":".$inode} = {inode => $inode, dev => $dev,
+ hit => 0, miss => 0};
+ }
+ return $records{$p}{$dev.":".$inode};
+}
+
+sub minor
+{
+ my $dev = shift;
+ return $dev & ((1 << 20) - 1);
+}
+
+sub major
+{
+ my $dev = shift;
+ return $dev >> 20;
+}
+
+sub print_pagecache_hit_ratio
+{
+ print "[process list]\n";
+ while(my ($pid, $v) = each(%records)) {
+ print "o $pid\n";
+ printf(" %12s %10s %10s %10s %10s\n", "", "",
+ "cache find", "cache hit", "cache hit");
+ printf(" %12s %10s %10s %10s %10s\n", "device", "inode",
+ "count", "count", "ratio");
+ printf(" %s\n", '-' x 56);
+ foreach my $r (sort { $$a{inode} <=> $$b{inode} } values %$v) {
+ printf(" %12s %10d %10d %10d %9.2f%%\n",
+ major($$r{dev}).":".minor($$r{dev}), $$r{inode},
+ $$r{miss} + $$r{hit}, $$r{hit},
+ $$r{hit} / ($$r{miss} + $$r{hit}) * 100);
+ }
+ print "\n";
+ }
+}

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Next message: stanley.miao: "Re: [PATCH 11/17] MTD: nand: fix bug that prevented write of morethat one page by ->write_oob"
Previous message: Keiichi KII: "[RFC PATCH -tip 1/2 v3] tracepoints: add tracepoints for pagecache"
In reply to: Keiichi KII: "[RFC PATCH -tip 1/2 v3] tracepoints: add tracepoints for pagecache"
Next in thread: Ingo Molnar: "Re: [RFC PATCH -tip 0/2 v3] pagecache tracepoints proposal"
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